Method of feeding yarn to a knitting place on a textile machine

ABSTRACT

A METHOD OF FEEDING YARN TO A KNITTING PLACE ON A TEXTITLE MACHINE, SUCH A KNITTING, WEAVING OR WINDING MACHINE, WHEREIN THE YARN IS DRAWN OFF A BOBBIN AND TANGENERALLY WOUND UNDER TENSION ONTO A STORING DRUM IN THE FORM OF A PLURALITY OF WINDINGS. THE YARN AT THE WINDING-ON STAGE BEARS AGAINST A FREE SURFACE SECTION OF THE STORING DRUM BEING MOVED IN THE AXIAL DIRECTION OF THE STORING DRUM BY PRESSURE AT LEAST ON THE LAST FORMED WINDING BY MEANS OF A SLIDING ELEMENT WHICH IS MOVABLE IN THE LONGITUDINAL DIRECTION OF THE SURFACE OF THE DRUM AND/OR FORMS AN ACUTE ANGLE BETWEEN ITSELF AND THE OUTER FACE OF THE SAID DRUM AT LEAST PART OF THE DRUM PERIPHERY AND FINALLY BEING WITHDRAWN FROM THE STORING DRUM IN AN AXIAL DIRECTION. AN IRREGULAR BALL OF YARN HAVING ONE OR MORE LAYERS AT LEAST IN PARTS IS FORMED BY REDUCING THE WINDING TENSION OF THE YARN RELATIVE TO THE WINDING TENSION TO BE MAINTAINED IN A ONE-LAYERED WINDING AS A RESULT OF THE PRESSURE WHICH IS EFFECTIVE IN AN AXIAL DIRECTION.

Sept. 21, 197 1 K. I. J. ROSEN 3,505,975

METHOD OF FEEDING YARN TO A KNITTING PLACE ON A TEXTILE MACHINE Filed Jan.-9. 1970 3 Sheets-Sheet l FIG.1

g r if INVENTOR K464 L946 M64 F0307 Sept. 21, 1971 K. I. J. RQSEN I 3,606,975

METHOD OF FEEDING YARN. TO A KN ITTING PLACE ON A TEXTILE MACHINE Filed Jan. 9, 1970 3 Sheets-Sheet z INVENTOR #JPL A946 1/[ @0657 WL, awe/7 A sq. 21, 19-11 METHOD 0F FEEDIAG YARN TO A KNITTING PLACE ON A TEXTILE MACHINE Filed Jan. 9. 1970 3 Sheets-Sheet 5 INVENTOR K146! 646M051 FflM/V United States Patent 3,606,975 METHOD OF FEEDING YARN TO A KNITTING PLACE ON A TEXTILE MACHINE Karl Isac Joel Rosen, Villa Haga, Ulricehamn, Sweden Filed Jan. 9, 1970, Ser. No. 1,635 Claims priority, application Germany, Jan. 22, 1969, P 19 03 133.5 Int. Cl. B65h 51/20 US. Cl. 242-47.12 1 Claim ABSTRACT OF THE DISCLOSURE A method of feeding yarn to a knitting place on a textile machine, such as a knitting, weaving or winding machine, wherein the yarn is drawn oif a bobbin and tangentially wound under tension onto a storing drum in the form of a plurality of windings. The yarn at the winding-on stage bears against a free surface section of the storing drum being moved in the axial direction of the storing drum by pressure at least on the last formed winding by means of a sliding element which is movable in the longitudinal direction of the surface of the drum and/ or forms an acute angle between itself and the outer face of the said drum at least over part of the drum periphery and finally being withdrawn from the storing drum in an axial direction. An irregular ball of yarn having one or more layers at least in parts is formed by reducing the winding tension of the yarn relative to the winding tension to be maintained in a one-layered winding as a result of the pressure which is effective in an axial direction.

BACKGROUND OF THE INVENTION The invention relates to a method of feeding yarn to a knitting position on a textile machine, such as a knitting, weaving or winding machine, wherein the yarn is drawn off a bobbin and tangentially wound under tension onto a storing drum in the form of a plurality of windings, the yarn in the starting zone being placed against a free section of the surface of the storing drum, transported in an axial direction of the drum by pressure on at least the last winding by means of a sliding element which is movable in a longitudinal direction of the surface of the drum at least over part of the drum periphery, and finally being withdrawn from the drum in an axial direction.

With a method of this kind the yarn is to be fed to the knitting position on a textile machine, for example, a weaving, knitting or winding machine, said yarn having a tension which is as low and as constant as possible.-

This desired effect is obtained by interposing a storing drum which forms an intermediate storing means between the bobbin and the knitting position and by the axial Withdrawal of the yarn from the drum. In this connection the storing drum is usually associated with a monitoring device which initiates the winding operation when the yarn supply falls below a given limit on the drum, and stops the winding operation when the yarn supply exceeds an upper limit.

A method of this kind is already known. For the axial movement of yarn windings a spoke Wheel inside the storing drum is inclined relative to the longitudinal axis of the drum and is pivotably mounted about a transverse axis, the arms of said spoke wheel penetrating openings in the wall of the drum. Due to the inclined position of the spoke wheel, the arms form an acute angle to the surface of the drum over part of a periphery. The first yarn winding engages the arms of the spoke wheel having a greater inclination so that the former is displaced by the arms in an axial direction, thereby also moving the previously formed winding. The axial movement of the yarn winding is, moreover, produced by the spoke wheel which is spring-loaded in the pivoting direction. This known method only relates to a winding position on the storing drum.

To move the yarn windings in axial directions of the storing drum, it is also known practice to arrange a cone, tapering in the direction of movement of the yarn windings, in the section of the drum to which the yarn is fed. The winding yarn passes under the cone so that the newly formed winding bears against the preceding winding and displaces it axially on the storing drums. The newly formed winding therefore exerts an axial pressure on the previous windings whereupon the entire yarn supply moves in an axial direction of the storing drum.

Finally it is also known practice to effect the axial movement of the yarn supply on the storing drum by arranging belt drives which extend longitudinally along the surface of the storing drum, the yarn windings being laid upon the outer sides of the belt. The sides of the belt moving in the direction of the point of yarn withdrawal guide the yarn windings simultaneously. In this arrangement, therefore, the movement is not effected by the axial pressure on the last winding.

It is common to all the known arrangements that great importance is attached to the forming of any one yarn winding position on the storing drum. In the known arrangement it is not considered possible to obtain a constant and low tension at the point of yarn withdrawal when a plurality of winding positions overlap one another. The desire to form only one yarn winding position on the storing drum necessitates the winding of the yarn onto the drum at a tension which can be low, but must nevertheless attain a value whereby the yarn windings are prevented from slipping over one another. The yarn windings must therefore be wound so tightly around the stor ing drum that no winding can slip under or over the adjacent winding. Two serious disadvantages are produced by having only one winding position on the storing drum: firstly, only a relatively small yarn supply can be formed when a storing drum is of a limited size for reasons of space. In the case of textile machines having a greater yarn consumption this necessitates frequent stopping and starting of the winding operation which is controlled by the device for monitoring the yarn supply. This entails corresponding problems of control and wear. Secondly, the result of the yarn being relatively tightly wound about the drum is that the yarns consisting of individual fibers which unavoidably project sideways out of the surface of the yarns are gripped in parts by the adjacent yarn winding on the surface on the yarn. If the yarn is then withdrawn from the storing drum, it offers a slightly greater resistance to withdrawal in places where projecting fibers are backed by the following winding. During yarn withdrawal there is produced so-called tugging, i.e., irregular variations in tension which make it impossible to ob 'tain the desired constant and low yarn tension.

Also known is a yarn feeding device wherein an intermediate yarn storing means having a plurality of layers is formed on a storing drum. A tightly wound bobbin is formed on the storing drum by means of a cross winding arrangement and displaced in the axial direction of the storing drum by means of a conical extension thereon. In this case, however, yarn withdrawal can only be effected from the interior of the intermediate bobbin. For this purpose the intermediate bobbin must be a form of cone-shaped bobbin, the withdrawal end of which projects above the drum in an exposed position. In order to form this cone-shaped bobbin a conical winding body which is displaced on the intermedaite bobbin during the increasing formation of the latter and is then removed must first be mounted on the storing drum. This method may be practicable with winding machines, but it is not possible with most other textile machines to introduce an additional winding body onto the drum and then to remove it later at the beginning of each operation and whenever the yarn is changed.

The problem underlying the invention is to provide the method of the type described above so that a relatively large yarn supply can be formed on a storing drum of a given size and a low and constant tension can be maintained during yarn withdrawal.

This problem is solved in accordance with the invention because an irregular ball of yarn having one or more layers at least in part is formed by reducing the winding tension of the yarn relative to the tension to be maintained in the winding having one layer as a result of the pressure acting in an axial direction.

The invention abandons the previously pursued prin ciple of forming only one layer or a constantly wound intermediate bobbin on the storing drum and instead proposes an irregular ball of yarn having two or more layers on the storing drum. It has been unexpectedly found that an extremely constant and low tension prevails during yarn withdrawal despite the formation of the ball of yarn on the drum. This is presumably due to the fact that a plurality of layers is firstly formed in the relatively loosely wound ball of yarn in the feed zone as a result of the axial pressure exerted on the last winding to be fed. However, the layer becomes thinner again in the direction of the point of withdrawal and becomes disentangled immediately before withdrawal to the extent that there is essentially only one layer of yarn windings lying relatively loosely in juxtaposition. The yarn is drawn from this one-layer section, in which it is obvious that the loosely lying yarn windings do not grip one another at this point and, in particular, no laterally projecting fibers adhere to the surface of the drum. This results in the main advantage of the invention, namely, the extremely constant and low tension during yarn withdrawal. In addition, another advantage is obtained in that a fairly large yarn supply can be formed on a drum of given size because the yarn is stored on the drum in a plurality of layers forming a ball. In this way the winding operation does not need to be stopped and started as frequently as in the past.

The magnitude of yarn winding tension to be provided when the method according to the invention is carried out depends on the quality of the yarn, but usually lies between 0.3 g. and 10 g. approximately. Optimum results are obtained when most yarns have tensions lying between 1 g. and 6 g. approximately.

The invention is described below with the aid of a practical embodiment in combination with the drawings.

FIG. 1 shows a side view of a yarn feeding and storing device suitable for carrying out the method according to the invention,

FIG. 2 shows a schematic view of the storing drum according to FIG. 1, the yarn supply having been wound FIG. 3 shows a schematic cross section through the yarn winding in the starting and finishing zones of the yarn,

FIG. 4 shows a view corresponding to FIG. 3 in the central section of the yarn winding, and

FIG. 5 shows an enlarged longitudinal section through the yarn winding.

FIG. 1 shows a bobbin 2 mounted about the vertical pin 3 on a carrier arm 1 which is connected to an unshown frame of a textile machine, for example, a knitting, weaving or winding machine. A yarn F is drawn upwards off this bobbin and tangentially fed through or by a plurality of yarn guiding elements 4, 5 and 6 of a storing drum which is generally designated by reference numeral 7. A yarn retarding means 8 of known construction, for example, a disc brake, is introduced in the path of the yarn F between the bobbin 2 and the storing drum 7.

The storing drum 7 is rotatably mounted in the lower side of the carrier arm 1 and can'be rotatably driven in the winding direction by a motor which is not shown In the illustrated embodiment it has a circular cylindrical edge provided with rods acting as the actual winding member. The yarn is wound onto the outer walls of the rods which form the cage. A spoke wheel 9 which is not visible in detail in the drawing, but can be seen in FIG. 5, is mounted inside the storing drum and inclined relative to the longitudinal axis of the drum 7 and subjected to stress by a spring F in the direction of inclination. Its spoke arm's 9a penetrate the rods 7a of the storing drum and are connected at their free ends by a sliding ring-9b which bears tightly against the outer face of the rods 7a in the vicinity of the drum 7 to which the yarn F is fed. The spoke wheel 9 and the sliding ring 911 are pivotable in the direction of the double arrow P. The electric motor of the drive of the storing drum is controlled by the pivoting movement of the spoke wheel through a micro switch.

A yarn supply V which is shown by broken lines in FIG. 1 is formed on the storing drum 7. When this supply reaches an upper limit, its resistance to displacement along the drum is increased by the sliding ring 9b of the spoke arm 9a to such an extent that the sliding ring and the spoke wheel are pivoted whereupon the drive of the drum is switched off. If the yarn supply V falls below a given limit, the sliding ring can pivot downwards again with the spoke wheel, thereby switching the drive of the drum on again. Further details of the known apparatus and the conventional mode of operation are given in U.S. Pat. No. 3,419,225.

The yarn F is drawn from the storing drum 7 by a retarding ring 10 which surrounds the lower edge of the drum 7 with a resilient arrangement. The section of yarn unwinding in an axial direction is designated by reference Fa in the drawing and is guided through an eye 11 to a working position on the textile machine. The section of yarn being wound on tangentially is designated by reference Fz.

Details of the winding on and withdrawing of the yarn F from the storing drum 7 can be seen in FIGS. 2-5.

According to FIG. 2 in which the storing drum 7 is shown as a single cylindrical member, the section of yarn Fz being wound on engages on a free surface section 7' of the storing drum. The first winding to be formed is displaced in the axial direction of the drum 7, downwards in the drawing, by the inclined sliding ring 9b or the spoke arms 9a. The yarn supply lying in front is displaced by the pressure exerted by the first winding and naturally offers frictional resistance to this displacement. The section of yarn Fa is withdrawn from the lower end of the yarn supply V.

The section of yarn Fz is wound onto the storing drum 7 at a low tension of, for example, 0.5 g. by corresponding adjustment of the yarn retarding means 8. In the manner shown in FIG. 3 the first winding W of the yarn bears relatively uniformly against the periphery of the drum 7; the windings, however, are irregularly deformed by the increasing displacement of the yarn supply along ,7 the drum 7 and therefore the increasing frictional resistance, for example, as shown in the case of a winding W in FIG. 4. Parts of the winding W engage on the surface of the drum 7, but extend through other sections at a distance from the drum surface, then return towards the surface, etc. As a result of the acute angle W between the spoke arms 9a and the surface of the drums 7 and due to the mobility of the arms 9a and the sliding ring 9b in the longitudinal direction of the drum 7, the yarn windings slip partially over and under one another, the yarn supply V thereby forming a ball K, the cross section of which is schematically represented in FIG. 5. Following the first winding W two or more yarn windings partially overlap one another in the ball K. The result is therefore an irregular ball of yarn compressed in the axial direction of the storing drum 7. The section of this ball of yarn which can be seen in FIG. 5 resembles an aerofoil on its outer side. The remarkable feature in the design of this ball resides in the thickness of the ball tapering in the direction of yarn withdrawal so that the last windings W again form only one relatively loose layer of yarn. This can be clearly seen in FIG. 5. The yarn F is withdrawn from this single loose layer, in which case no fluctuations in tension can occur in the unwinding section of yarn Pa.

The winding tension which is necessary to form a ball, of the type illustrated in cross section in FIG. 5, on the storing drum 7 depends on the quality of yarn. The most advantageous winding tensions for yarns of different qualities are listed below:

G. Crimped multi-filament yarn made of polyamide,

140 denier 1.5-12 Crimped multi-filament yarn made of polyester,

150 denier 2.5-l2 Monofilament yarn made of polyamide, 20

denier 1.4-7.8 Twisted cotton 1/36 1-13 The operation is carried out at a lower limit without a separate retarding means in the winding section of the yarn. In this connection the low winding tension which is highly practicable and even advantageous was only produced by resistance to friction and withdrawal.

The invention is not limited to the illustrated embodiment. In particular, the invention may also be applied when the storing drum 7 is stationary and the yarn is wound thereon by a rotating winding arm. Furthermore, the storing drum can also have a dilferent form; for example, it can be a closed cylinder having a polished surface. The cross-sectional shape of the storing drum is unimportant; the circular shape could for example be replaced by any desired polygonal shape. The axial movement of the yarn supply V can also be eifected by means other than the sliding ring 9b. For example, on the outside of the storing drum a sliding element can engage in longitudinal grooves of said drum. In addition, the winding operation could also be controlled by other arrangements in place of the described spoke wheel. For example, there may be provided a photoelectric control device which operates by light reflected from the surface of the storing drum.

6 What I claim is: 1. In a method of feeding yarn to a textile machine wherein the yarn is withdrawn from the source and wound under tension in a plurality of windings onto a storing drum, the yarn at the winding-on zone bearing against an unoccupied surface portion of the storing drum and being moved in an axial direction of the storing drum by a mechanical pressure exerted on at least the last formed winding and wherein the yarn is withdrawn from the storing drum at a withdrawal zone spaced axially from the winding-on zone thereof, the improvement comprising the further steps:

controlling the tension of the yarn fed to the drum to maintain said tension at a value, in view of the nature of the yarn, materially less than that required to maintain only a single layer on said drum and accumulating said yarn in a multi-layered manner on said drum; withdrawing the yarn from adjacent the surface of the drum at a withdrawal zone axially spaced from the winding-on zone and effecting said withdrawing in a substantially axial direction; thereby forming a ball of irregularly wound yarn in layers on said drum adjacent to and extending a short axial distance from the point of application of said axial mechanical pressure and migrating said layers from the region of said ball to said withdrawal zone with said layers appearing there as a single wound layer which can be withdrawn therefrom at a constant tension.

References Cited UNITED STATES PATENTS 9/1947 Miles et a1. 24247.12X 12/1968 Rosen 24247.12

FOREIGN PATENTS 10/1967 U.S.S.R. 24247.01 

